diff options
author | Bart Van Assche <bvanassche@acm.org> | 2020-03-09 21:26:22 -0700 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-04-24 08:00:25 +0200 |
commit | df92d602b7305702bb784f83db4c0ccb125a5a17 (patch) | |
tree | 70453ed309cf0eb42fee88b1f0efe6a4c261f5b4 /drivers/block | |
parent | a1200a6c59585b37c0fd7d180c41d856a427596c (diff) |
null_blk: Handle null_add_dev() failures properly
[ Upstream commit 9b03b713082a31a5b90e0a893c72aa620e255c26 ]
If null_add_dev() fails then null_del_dev() is called with a NULL argument.
Make null_del_dev() handle this scenario correctly. This patch fixes the
following KASAN complaint:
null-ptr-deref in null_del_dev+0x28/0x280 [null_blk]
Read of size 8 at addr 0000000000000000 by task find/1062
Call Trace:
dump_stack+0xa5/0xe6
__kasan_report.cold+0x65/0x99
kasan_report+0x16/0x20
__asan_load8+0x58/0x90
null_del_dev+0x28/0x280 [null_blk]
nullb_group_drop_item+0x7e/0xa0 [null_blk]
client_drop_item+0x53/0x80 [configfs]
configfs_rmdir+0x395/0x4e0 [configfs]
vfs_rmdir+0xb6/0x220
do_rmdir+0x238/0x2c0
__x64_sys_unlinkat+0x75/0x90
do_syscall_64+0x6f/0x2f0
entry_SYSCALL_64_after_hwframe+0x49/0xbe
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Cc: Johannes Thumshirn <jth@kernel.org>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Ming Lei <ming.lei@redhat.com>
Cc: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'drivers/block')
-rw-r--r-- | drivers/block/null_blk.c | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/drivers/block/null_blk.c b/drivers/block/null_blk.c index e9776ca0996b..b4078901dbcb 100644 --- a/drivers/block/null_blk.c +++ b/drivers/block/null_blk.c @@ -1593,7 +1593,12 @@ static void null_nvm_unregister(struct nullb *nullb) {} static void null_del_dev(struct nullb *nullb) { - struct nullb_device *dev = nullb->dev; + struct nullb_device *dev; + + if (!nullb) + return; + + dev = nullb->dev; ida_simple_remove(&nullb_indexes, nullb->index); |